In the present description and in the following claims, reference is made to straight handlebars as opposite to handlebars having dropped end portions of the type normally used in race bicycles. The straight handlebars have end hand-grips extending substantially along a horizontal direction orthogonal to the longitudinal symmetry plane of the handlebar. Handlebars of this type are usually employed for example on city bicycles, mountain bikes and touring bicycles, these latter being intended as bicycles generally having the features of a race bicycle, but provided with a straight handlebar rather than a handlebar with dropped end portions.
Gear change control devices are already known, particularly for bicycles having straight handlebar, comprising a support which can be fixed to the handlebar, a first gear change control member and a second gear change control member, wherein said first control member is pivotally mounted on said support and has a control portion which, in the mounted condition of said device on said handlebar, is movable forwardly in the longitudinal direction of the bicycle from a rest position to an operative position.
In a first category of devices of the above indicated type, both the first and second gear change control members are arranged so as to have their respective control portions both movable below the handlebar (see for example EP 0 361 335 B1), and both arranged to be operated by the cyclist by pushing them forwardly in the longitudinal direction of the bicycle, with the thumb of the hand which grips the adjacent handgrip of the handlebar. However, some of the above mentioned known devices are not completely easy to use since, although enabling actuation of the gear change without requiring that the hand is moved away from the handgrip on the handlebar, they since involve a variation of the hand's position on the handlebar, the variation being dependent upon whether one desires to actuate the first or the second gear change control members.
A further drawback of the known devices of the above indicated type lies in the possibility that if the cyclist actuates the gear change without actually looking at it, there is the potential to actuate one control member instead of the other. On the other hand, diverting the cyclist from the road presents its only danger.
Devices are also known in which only one of the two control members is actuated by pushing it forwardly; the other control member is formed by a lever whose control end is located ahead of the handlebar with reference to the longitudinal direction of the bicycle and is actuated by pulling it backwardly. See EP-A-0 785 128.
In order to overcome all the above mentioned drawbacks, the invention provides a gear change control device comprising a support for fixing to the handlebar, a first gear change control member and a second gear change control member. The first control member is pivotally mounted on said support and has a control portion which is movable forwardly in the longitudinal direction of the bicycle from a rest position to an operative position. The control portion being arranged behind the handlebar with respect to said longitudinal direction, and extending at least partially at a position lying substantially at the same level of the handlebar, with respect to a vertical direction in the condition of use of the handlebar.
Further preferred features of the control device of the invention are specified in the annexed claims.
In the preferred embodiment, the control portions of both control members can be controlled by pushing them forwardly with the thumb and without changing the position of the hand on the handgrip of the handlebar, depending upon whether one member or the other must be actuated. It is indeed possible to reach both the control members by holding the hand in the same position and moving only the thumb.
Furthermore, since the control portion of one or both of the two control members (12 or 14) is at least partially located so that it lies substantially in the same plane as the handlebar with respect to a vertical direction (i.e. substantially neither above nor below the handlebar). This easy reference position reduces the risk that the cyclist inadvertently actuates one member instead of the other when the operation is performed without diverting the eyes away from the road.
The above mentioned first and second control members control a bicycle derailleur, which can be either the rear or front derailleur.
In one embodiment, the above mentioned first and second control members control an actuating mechanism carried by the above mentioned support and connected to the derailleur through a flexible cable.
In a variant, the above mentioned first and second control members control switches carried by said support and forming part of an electronic device controlling an actuator for the derailleur, which can be made for example according to the teachings of U.S. Pat. No. 5,480,356.
According to a further preferred feature of the invention, the above mentioned support for the gear change control device is integrated with a support to which a brake actuating lever is articulated.
In the case that the two control members control an actuating mechanism, the preferred embodiment has the first and second control members both constituted by pivotable levers which return to their rest or home position after being operated. Also in the preferred embodiment, the first control member is a release control member adapted to control a release mechanism, i.e. a mechanism which temporarily leaves a derailleur control cable free to move under the action of a spring means associated with the derailleur. Release mechanisms of this type are known, see for example GB-A-2,012,893. With this feature, the reduced operating stroke of the first control member allows it to be operated a position substantially in the plane of the handlebar. This provides the further advantage that the handlebar acts as a stop element with respect to such a control member, thus avoiding any risk of excess force being applied to the control member.